Malignant fibrous histiocytomas (MFHs) are the most common soft-tissue sarcoma of adulthood; they have a male preponderance, and often involve the extremities and retroperitoneum, but a primary MFH of the urinary tract is extremely rare. We report a 62-year-old male with MFH of the left ureter, in which a left nephroureterectomy with bladder cuff resection was performed. The diagnosis was established on the basis of the pathologic microscopic findings and immunohistochemistry. Most studies recommend adjuvant chemotherapy or radiotherapy for these tumors, but the role of these treatments needs further investigation.